The present invention generally relates to roller coater type apparatus which are used to apply laminate to a substrate, and more particularly to a roller coater for coating one or both sides of a sheet metal strip fed along a predetermined path, such as for example into a press.
In the metal forming industry, apparatus commonly known as roller coaters are used to apply a lubricant type laminate to sheet metal strip substrate. The lubricant laminated sheet metal is then typically fed into a press which punches and forms the sheet metal into patterns as desired. The lubricant performs the desirable function of lubricating the tooling of the press when it is working the metal. Sometimes it is desirable to switch the type of lubricant depending upon the particular types of operations being performed to the metal. It is usually desirable to coat both sides of the sheet metal strip with lubricant although it is occasionally desirable to coat only one side of sheet. It may also be desirable to change the width of the laminate application depending upon the width of the metal strip or the operations of the downstream press.
In the sheet metal lubrication industry, the typical roller coater apparatus includes upper and lower roller coater assemblies for application of lubricant to both sides of the sheet metal substrate. The upper and lower roller coaters include respective applicator rolls which pinch the sheet metal strip therebetween to apply lubrication to the top and bottom sides of the sheet metal strip. The applicator rolls are journalled in bearings at their ends for rotation about parallel rotational axes.
Heretofore, prior roller coater apparatus have had several drawbacks. One drawback is that there is typically a substantial amount of downtime and labor required when changing applicator rolls to apply different types of laminate. Another drawback is that roller coaters have less than desirable lubricant application that is either non-uniform or uneven, particularly where a small application rate is desired. This often results in wasted lubricant or alternatively a poorly lubricated press. Yet another drawback is that roller coater apparatus have not been able to adapt to changes in feed of the sheet metal strip.
One aspect of the present invention is directed towards the novel provision of pneumatic vertical floatation of the top and bottom roller coater assemblies of a roller coater apparatus. According to this aspect, the roller coater apparatus includes top and bottom roller coater assemblies which are adapted to pinch metal strip therebetween to selectively coat one or both sides of the metal strip with lubricant. A pneumatic cylinder assembly is provided that is capable of moving upward and downward along with variations of the vertical height of the metal strip. To accomplish this, at least one pneumatic cylinder assembly is provided that includes top and bottom pneumatic cylinders. The top pneumatic cylinder operates the upper roller coater assembly while the bottom pneumatic cylinder operates the lower roller coater assembly. The top and bottom cylinders have fluidically connected chambers or a common chamber that equalizes pressure and allows the cylinders to move upward and downward in unison without changing the pinching force applied to the sheet metal strip therebetween.
Another aspect of the invention is directed toward a novel support arrangement for the applicator roll of a roller coater apparatus which is used to apply lubricant or other laminate to metal strip. The apparatus generally may include top and bottom roller coaters (but may also be applicable to a single roller coater) which are adapted to pinch metal strip or other substrate material therebetween in an engaged position. The support of the applicator roll is accomplished by at least two discrete supports such as support rolls that engage the applicator roll at different angular locations such that the applicator roll may be carried without the need to journal the ends of the applicator roll.
A further aspect of the present invention is directed towards the provision of a novel lubricant applicator assembly in which a lubricant dispensing head applies lubricant directly to the surface of the applicator roll. The dispensing head has a concave recessed surface that receives the outer periphery of the applicator roll. The dispensing head includes an elongated outlet in the recessed surface which receives laminate and applies laminate directly to the applicator roll.
Other object and advantages of the invention will become more apparent from the following detailed description when taken in conjunction with the accompanying drawings.